Supercharger control



M. J. KITTLER SUPERCHARGER CONTROL June 13, 1950 5 Sheets-Sheet 1 Filed July 26, 1946 INVENTOR.

June 13, 1950 M. J. KITTLER SUPERCHARGER CONTROL 5 Sheets-Sheet 2 Filed July 26, 1946 MJKZ' Illa) INVENTOR.

June 13, 1950 M. J. KITTLER SUPERCHARGER CONTROL 5 Sheets-Sheet 3 Filed July 26, 1946 INVENTOR.

Patented June 13, 1950 STATES @PATsNr QFFICE.

George Holley nd Earl Holl y Application J uly 26, 1946, Serial No. 686,579

4 Claims. 1

The object of this invention is to provide a manual and automatic control, of a Roots blower type of supercharger, on an ordinary truck engine.

An additional object is to substitute an exhaust driven supercharger for a. Roots blower.

I have found that it is desirable to first unload the supercharger at the critical speed and then close the throttle of the carburetor to prevent the engine racing. If these two operations take place simultaneously the engine will hunt. The critical safe speed referred to is the safe maximum speed for this particular engine which speed is reduced by the increased load imposed by supercharging.

Fig. 1 shows diagrammatically the preferred form of my invention. Fig. 2 shows one method of connecting the foot control to both the carburetor and to the engine throttle control. Fig. 3 shows the substitution of an exhaust driven supercharger for the mechanically driven one shown in Fig. I.

In Fig. I I'll is the air entrance, and- I Z is the fuel nozzle discharging into the venturi M. A low speed nozzle is also shown but as this is no part of this invention full details'are omitted.

I8 is the carburetor throttle controlled automatically by lever 19. Throttle I8 is manually controlled by the lever 20. When the foot is 01f the foot pedal the throttle is shut by the spring 2| so that the throttle 18 may be oiosed at will by the mechanism shown in Fig. 2. i

"A centrifugal governor is shown having a shaft 22 driven at engine speed or some fraction thereof. 24 is the governor weight held back by the tension spring 26 in the revolving housing 28. 30 is the contoured needle which controls the opening of the throttle in the outlet from the supercharger and the closing of the throttle in the outlet from the carburetor.

Below-throttle pressure is connected through the restriction 32 which is connected to the pipe 34 which pipe is connected to the chambers 36 and 38. These chambers contain springs 48 and 42 which engage with diaphragms 44 and 48 and push them to the left. These diaphragms are connected with two throttles l8 and 48 so that the throttle I8 is pushed open and the throttle 48 is pushed closed by the springs 48 and 42. In addition the throttle 48 may be manually opened by moving the lever 18 clockwise. (See Fig. 2.) A Roots blower 58 is driven by the engine by means not shown and takes air from its air entrance 52 and delivers air under pressure to the pipe 54 which leads to the air entrance in.

2 A relief outlet 56 contains the relief outlet throttle valve 48. There is also a safety valve 58 provided for an obvious reason.

The chamber 60 to the left of the diaphragm 46' is connected through the pipe 62 to the passage 56.

The housing which contains the governor mechanism 24-26-28-38, is connected to the passage 54 by the pipe 66 so that maximum pressure exists in the chamber 65.

In Fig. 2 70 is the foot pedal, 12 is the throttle control rod which engages with the lever 28, which lever engages with throttle lever is so that the spring 21 tends to close the throttle 18 when the foot is 01f the pedal. The rod 12 carries an adjustable stop 14 which, when the pedal 10 is depressed far enough to open, throttle l8, engages with a rod 16, which rod 16 engages with a lever 18, which lever 18' engages with a second throttle lever 88. The tension spring 84 holds the throttle 48 wide open as the lever 88 engages with the throttle 48 under the influence of the spring 42- (Fig. 1).

In Fig. 3, 32 is the restricted connection from the inlet manifold to the inside of the governor. The pipe 65 is connected with the chamber 68,

and through the pipe I00, with the housing 65 containing the governor mechanism 24-2638. The pipe 35 and 34 connects the inside of the governor mechanism with the chambers 38 and 36 and thus subjects the diaphragm 44 and 46 t0 suction. The rod 12 engages with the throttle lever I82 and is adapted to close the throttle It. The opening of the throttle I8 is responsive to the pressure differences acting on opposite sides of the diaphragm 44.

The lever 18', which is free to rotate on the throttle shaft I84 of throttle 48, engages with the lever which is mounted on and connected to the throttle shaft of the throttle 48. In the position shown the lever 18 is holding the throttle 48 wide open by means of the pin I82 projecting laterally from the lever 18 and engaging with the lever 80. The exhaust gases enter the exhaust outlet at 92 and flow through bypass 94 past the gas turbine 88 and eventually flow out of the exhaust pipe 92. The suction applied through the inlet I6, that is, the suction transmitted through the restriction 32, imposes differential pressure forces acting on the diaphragm 44 and 45. Springs 48 and 42 are selected so that at excessive speeds when carburetor throttle i8 is wide open and exhaust throttle 48 is closed throttle 48 is opened first and then the throttle i8 is closed. The movement of the rod I2 to the right permits the lever 18 to move to the right after the throttle l8 has been permitted to open because the stop 14' engages with the lever 18 and finalls the throttle 48 is permitted to close in response to the closing of the needle valve 30 which permits the spring 42 to push the diaphragm 46 in an upward direction and thus close the throttle 48.

Operation In Figs. 1 and 2 when the foot pedal is first depressed the throttle i8 is opened by the action of the spring 40 and thereafter the spring 42 pushes the lever 80 and the throttle 48 into the closed position after the stop 14 has engaged with the rod 16 so as to move the lever 18 counterclockwise and stretch the spring 84 and take the load ofi the lever 80 which is permitted to respond to the spring 42.

The engine speeds up and eventually the speed approaches the safe speed. It is most desirable for reasons of fuel economy, engine life and the life of the Roots blower that the load be first removed from the Roots-blower. The contour of needle valve 30 and the stifiness of spring 42 are selected so that the throttle 48 opens first, and second the carburetor throttle valve l8 closes. The valve 3!! as it moves to the right imposes the suction below throttle l8 to the right of the dia phragm 4B and 44, but diaphragm 46 is the first to move. Throttle 48 opens before throttle l8 closes.

In Fig. 3 the equivalent parts of Figs. 1 and 2 have the same numbers. In addition a pipe Bil is shown connecting the chamber 64 to the pipe 54.

The supercharger 5D is replaced by an exhaust driven supercharger 9D. The exhaust pipe 92, when the throttle valve 48 is closed, diverts the exhaust through the passage 94 which drives the turbine 96. Otherwise the device is substantially identical with that shown in Fig. 1.

The throttle control rod 12' first permits the throttle H! to respond to the compression spring 40 in chamber 36 and thus it opens the throttle [8. The throttle control rod 12 then continues to move to the right so that the stop I4 engages the lever l8, stretches the spring 84' and allows the lever 80 to respond to the spring 42. Then the valve 48 is closed and the exhaust flowing down 94 rotates the supercharger 90 by rotating the turbine 96.

What I claim is:

1. Automatic control means for a supercharged internal combustion engine having an engine driven supercharger connected to a carburetor having a carburetor throttle valve adapted to throttle the charge delivered by the carburetor to the inlet of said engine, a second throttle adapted to unload the supercharger whereby the supercharger becomes ineffective, a chamber, a moving wall therein connected to said carburetor throttle, a second chamber, a second moving wall therein connected to said second throttle, a yieldable means in each of said chambers adapted to move the carburetor throttle to its open position and to move the second throttle to the position in which said supercharger becomes effective, a centrifugal governor, a passage connecting one side of the moving walls in said chambers to said engine inlet on the engine side of said throttle, a restriction in said passage, a valve adapted when open to admit supercharged air to said passage, said valve being contoured so as to gradually control the pressure on each of said moving walls to oppose said yieldable means, governor controlled means for moving said valve, said yieldable means being so designed that the second throttle is moved to the position in which the supercharger becomes inoperative before the carburetor throttle is moved towards its closed position.

2. A device as set forth in claim 1 in which there are manual control means comprising a one way connection adapted to positively close said carburetor throttle, a second one way connection and yieldable means associated therein adapted to move said second throttle into the position in which it renders said supercharger ineffective, a manually operated link positively connected to said first one way connection, a second link positively connected to said second one way connection and slidably mounted on said first link, a stop on said first link adapted to operatively engage with said second link whereby the carburetor throttle must first be permitted to open wide in order to permit said second throttle to be moved by said second moveable wall and by the yieldable means associated therewith in the position in which the supercharger becomes operative.

3. A supercharger control for a throttle controlled internal combustion engine comprising an engine driven supercharger supplying air to said engine past said throttle, control means adapted to render said supercharger operative and inoperative, a centrifugal governor driven by said engine, a, chamber, a moving wall therein, a passage connecting the other side of said moving wall to the supercharger side of said throttle, a passage connecting both sides together so as to equalize the pressure on opposite sides of said moving wall, a valve therein operatively connected to and adapted to be closed by said governor at predetermined speeds, yieldable means engaging with said moving wall and with said supercharger control, means adapted to render said supercharger operative, additional supercharger control means for rendering said supercharger inoperative comprising a lever, yieldable means for holding the lever in a position to hold the control means in its inoperative position at all speeds, throttle control means adapted to move said additional con trol means after the throttle has been opened towards its wide open position whereby the supercharger can only operate after the throttle has been opened.

4. Means for regulating the speed of a throttle controlled engine with which a supercharger is associated comprising an engine driven two stage governor having two speeds, means controlled by the first stage of said governor for rendering the supercharger ineffective to increase the horsepower of said engine at the lower of the two governed speeds and means controlled by the second stage of said governor for closing the engine throttle at the higher of the two speeds of said governor.

MILTON J. KITTLER.

REFERENCES CITED UNITED STATES PATENTS Name Date Staley July 16, 1946 Number 

